Dypsis gautieri Rakotoarin. & J.Dransf., Kew Bull. 65(2): 298 (2010)

Primary tabs

no image available

Distribution

Map uses TDWG level 3 distributions (http://www.nhm.ac.uk/hosted_sites/tdwg/geogrphy.html)
Madagascarpresent (M. Rakotoarinivo & J. Dransfield, New species of Dypsis and Ravenea (Arecaceae) from Madagascar in Kew Bulletin 65. 2010)A
Known only from Daraina, in the north of Madagascar. (M. Rakotoarinivo & J. Dransfield, New species of Dypsis and Ravenea (Arecaceae) from Madagascar in Kew Bulletin 65. 2010)A

Habitat

  • Montane forest, crest of ridge; 1040 m. (M. Rakotoarinivo & J. Dransfield, New species of Dypsis and Ravenea (Arecaceae) from Madagascar in Kew Bulletin 65. 2010)A

Discussion

  • Because of the form of the leaves, this species is superficially like Dypsis pinnatifrons, although substantially smaller. However, the staminate flowers have three antepetalous stamens with broad sagittate anthers rather than three antesepalous stamens with narrow sagittate anthers. It thus belongs to group 18 of Dransfield & Beentje (1995), some species of which were originally described in a separate genus, Trichodypsis. It is the only member of the group to haverather broad lanceolate single-fold leaflets grouped in tight clusters. The species is named for the collector, Laurent Gautier who has done much to catalogue the plant diversity of Daraina, a northern outlier of rain forest in Madagascar. (M. Rakotoarinivo & J. Dransfield, New species of Dypsis and Ravenea (Arecaceae) from Madagascar in Kew Bulletin 65. 2010)A

Diagnosis

  • Rakotoarin. & J. Dransf. sp. nov. D. pinnatifrondi Mart. superficialiter similis sed staminibus 3 antepetalis vice antesepalis et floribus rotundatis instanter distinguibilis. (M. Rakotoarinivo & J. Dransfield, New species of Dypsis and Ravenea (Arecaceae) from Madagascar in Kew Bulletin 65. 2010)A

Conservation

  • Vulnerable [VU D2]. Rare species, less than 20 mature individuals have been seen but the species is located on the summit of mountains where access is difficult and the whole area is protected and managed by Fanamby NGO. (M. Rakotoarinivo & J. Dransfield, New species of Dypsis and Ravenea (Arecaceae) from Madagascar in Kew Bulletin 65. 2010)A

Description

  • Solitary palm. Stems erect, 2 - 5 m high, 1.8- 3.5 cm diam., internodes 2.1- 3 cm, green to grey brown, minutely scaly near the crown. Leaves c. 9 in the crown, pinnate; sheaths 17- 18.5 cm long, 2.8-3.5 cm wide, closed, forming a well defined crownshaft, minutely scaly in all parts and covered with tomentum in the upper part, auricles irregularly triangular, to c. 3 - 4 x 0.4- 0.6 cm, tattering; petiole absent or up to 2 cm long; rachis 45- 55 cm long, c. 0.5 cm diam., densely covered with scales, adaxially channelled at the base then triangular in the median and distal parts; leaflets 18- 22 on each side of the rachis, in groups of 2- 5, at intervals of 4 -9 cm, the leaflets within the group 0.5- 1 cm apart; proximal leaflets 11- 12.3 ?x 0.4-0.6 cm, median 18- 21 x 1.7- 2.2 cm, distal 12- 14 x 2-2.5 cm, lamina covered in scattered brown scales, main veins 3, apices 1.4 - 2 cm long. Inflorescence interfoliar, branched to 3- 4 orders, arching; peduncle c. 40 cm long, 0.8 cm wide, densely covered in brown scales; prophyll inserted c. 1 cm above the base of peduncle, c. 15x 1.5 cm, split to 2.4 cm in the distal part, scaly, keeled; peduncular bract persistent, inserted c. 15 cm above the base of peduncle, c. 19 x1.2 cm, beaked for c. 6 mm, split to 4 cm distally, with scattered scales; rachis c. 45 cm long, 2 . 8 mm diam., densely scaly, with 24 branched and 7 unbranched first order branches, proximal first order branches to 13 cm long, with 6 branched and 10 unbranched second order branches, proximally to 2 . 4 x 0.1-0.2 cm; rachillae 3 -5 cm long, c. 0.5 mm diam., densely puberulous; triads inserted at intervals of 1.2-3.8 mm. Staminate flowers with sepals imbricate, unequal, 2.2- 2.6 x 2.6- 2.8 mm, densely scaly, keeled,± asymmetrical; petals imbricate but valvate at the tip, 3.2- 3.8x 2.2 . 2.8 cm, striate, minutely puberulous; stamens 3, antepetalous, filaments short c. 1 mm long, erect, anthers broad, sagittate, with 2 locules neatly differentiated, 10 - 12x 5- 8 mm; staminodes 3, minute c. 0.4 mm high; pistillode hexagonal, c. 0.6 mm high. Pistillate flowers with sepals imbricate, unequal, 2.4- 2.9 x 2.6- 2.8 mm, scaly, asymmetrical, keeled; petals imbricate, 2.8- 3.4 x 1.8 -2.4 mm, striate, elliptic; gynoecium obovoid, 1.4- 2 x 1.5- 1.6 mm. Fruits unknown. (M. Rakotoarinivo & J. Dransfield, New species of Dypsis and Ravenea (Arecaceae) from Madagascar in Kew Bulletin 65. 2010)A

Materials Examined

  • MADAGASCAR. Antsiranana, Vohemar, Daraina, 13º13'39"S, 49º32'08"E, 11 Nov. 2004, L. Gautier et al. LG 4703 (holotype K!; isotype G!). (M. Rakotoarinivo & J. Dransfield, New species of Dypsis and Ravenea (Arecaceae) from Madagascar in Kew Bulletin 65. 2010)A

Bibliography

A. M. Rakotoarinivo & J. Dransfield, New species of Dypsis and Ravenea (Arecaceae) from Madagascar in Kew Bulletin 65. 2010